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1.
This paper presents an analysis of the accessibility of nodes in the Belgian road network. The intersection of roads are considered as the nodes and their connecting roads as the edges of a network. By means of the Dijkstra algorithm accessibility values are computed for each node by summing shortest travel times to a reference system of 158 nodes spread evenly over the Belgian territory. A comparison of the measured actual accessibility with that determined from an optimal situation provides an indication of the quality of directness of the Belgian road system. Accessibility and directness are shown cartographically. An isochronal map illustrates the access to Brussels. 相似文献
2.
Indicators of road network vulnerability to storm-felled trees 总被引：1，自引：0，他引：1
In this paper, we exemplify the use of simple indicators of wind storm vulnerability of the road network that can be derived from existing geographic datasets. We point out the possible utilization of the datasets, applying GIS techniques, for highlighting road sections that, due to adjacency of high forest stands, are sensitive to closure by storm-felled trees. Indicators reflecting the reduced access to different areas or to the population in need of emergency aid can be derived based on the parameter tree height along roads and road network analysis. As a case in this study, the methodology is applied to elderly people (+80 years) with possible need of daily care at home following a severe storm. A comparison to the extreme 2005 storm felling in southern Sweden reveals that only limited estimates of road network disruption due to storm-felled trees are possible using the indicators, as other factors, for example, wind direction, which determine the exact impact of a particular storm are not taken into account. However, the indicators and network analysis also provide a possibility to draw attention to locations where disruptions of the road network would have significant effects on the accessibility to large surrounding areas. Potential critical road closures can be identified and preventive measures considered locally at these points. 相似文献
3.
This paper presents an assessment of the avalanche hazard potential and the resulting risks on mountain roads for a 38.7-km-long
section of road no 76 (Siglufjarearvegur) in northern Iceland following a regional scale approach developed in the Alps. The
assessment of the individual avalanche death risk proved applicable to distinguish areas of avalanche hazard with a risk above
the accepted level, which should be given priority in following detailed investigations and the planning of possible protective
measures, from road sections where the avalanche death risk is low and accepted according to international practice. The cumulative
individual and collective avalanche death risks in the investigated road section provide a comparable measure for assessing
the avalanche hazard both within the Icelandic public road network and on an international scale. The case study on road no
76 in northern Iceland shows that a standardised regional scale risk-based approach is practical to determine, analyse and
assess the avalanche hazard situation on mountain roads in Iceland and guarantees comprehensible, reproducible and comparable
results as a basis for a sustainable planning of measures. 相似文献
4.
J. Steinbach Dr. 《GeoJournal》1991,24(4):387-404
Conclusion The function profiles established within the framework of this research project are available as data files and cartographical representations. They form a fundamental input in the proposed dimensioning method, for the establishment of suitable constructive principles of road sections (either within the framework of a review of the existing network or for the planning of new roads). Above that the system of location and road section related indicators constitutes an extensive information basis for regional and traffic planning. 相似文献
5.
Ponlathep Lertworawanich 《Natural Hazards》2012,64(1):873-886
Flood is one of the common natural phenomena anywhere. In the second half of 2011, Thailand has recently faced with the most devastating flood of her modern history. More than 3,330 national highways are damaged by this flood. Some roads are heavily destroyed while others are partially damaged and emergency relieves cannot access to the flooded areas. Food and medicine distribution in the central part of the country has by large been disrupted. As a consequence, highway restoration is an urgent responsibility of road authorities. This study presents the sequential highway network restoration decision model when budgets and resources are unknown. Highways are restored one by one in sequence. To determine an optimal restoration sequence, the model is formulated as a dynamic program where the primary objective is to sequentially restore roadways to minimize the travel demand loss for the disconnected network. Once the network is connected, the secondary objective is to sequentially restore roadways to minimize the network travel time where traffic assignment onto the network is based on user equilibrium concept. The heuristic solution method using particle swarm optimization technique is provided for practical size problems. A sample network is examined to investigate the solution characteristics. It is found that the proposed algorithm can provide good practical solutions to the sequential highway network recovery problems and is incorporated to the Thailand highway maintenance management system. 相似文献
6.
GIS-based estimation of flood hazard impacts on road network in Makkah city, Saudi Arabia 总被引：1，自引：1，他引：0
Gomaa M. Dawod Meraj N. Mirza Khalid A. Al-Ghamdi 《Environmental Earth Sciences》2012,67(8):2205-2215
Makkah city, Saudi Arabia, is periodically exposed to flash floods that result in major human and economical damages. That is due to several factors including its rugged topography and geological structures. Hence, precise assessment of floods becomes a more vital demand in development planning. A GIS-based methodology has been developed for quantifying and spatially mapping the flood characteristics. The core of this new approach is integrating several topographic, metrological, geological, and land use data sets in a geographic information system (GIS) environment that utilizes the curve number method of flood modelling for ungauged arid catchments. Based on the estimated flood volume of sub-basins, a hazard factor has been developed to quantify the expected hazard level for each road. Applying this proposed approach reveals that 21?% of the road network in Makkah city is subjected to low flood hazards, 29?% is facing medium hazards, and 50?% of roads are exposed to harsh flood impacts. The developed approach may be considered a digital precise method that can be easily re-run, in other situations or regions, to estimate flood hazards on roads. 相似文献
7.
Hot spot analysis based on network spatial weights to determine spatial statistics of traffic accidents in Rize,Turkey 总被引：1，自引：0，他引：1
H. Ebru Colak Tugba Memisoglu Y. Selcuk Erbas Sevket Bediroglu 《Arabian Journal of Geosciences》2018,11(7):151
The increased numbers of vehicles using roads in the world today are cause of traffic-related problems, and in this respect, road traffic accidents are an important topic relating to public health. Especially on the road connecting two border provinces, traffic accidents are increasing substantially in parallel with the quantity of transport facilities. By determining areas where traffic accidents result in deaths or injuries, accident prevention strategies can be developed. This study applies the spatial statistics techniques using Geographical Information Systems (GIS) to determine the intensity of traffic accidents (hot-spot regions) over 45 km of main routes in Rize Province, Turkey. Traffic accidents recorded in data spanning 5 years are combined with a geographical dataset for evaluation using hot spot statistical analysis. Unlike other studies, this study used hot spot analysis based on network spatial weights (an innovative review in the methods of determining traffic accident hot spots: “novel application of GIScience”) to identify black spots for traffic safety. To perform the analysis using Hot Spot Analysis: Getis-Ord Gi*, a generated network dataset and the spatial weights of the road data are used to generate network spatial weights. Then, Kernel Density method is used to define traffic accident black spots. Finally, these two methods are compared each other with visually. 相似文献
8.
M. Hadji Hosseinlou M. Sohrabi 《International Journal of Environmental Science and Technology》2009,6(2):309-314
Providing safety in roads for the purpose of protecting human assets and preventing social and economic losses resulted from road accidents is a significant issue. Identifying the traffic hot spots of the roads provides the possibility of promoting the road safety which is also related to investigate frequency and intensity of occurred accidents. Accidents are multidimensional and complicated events. Identifying the accident factors is based on applying a comprehensive and integrated system for making decisions. Therefore, applying common mathematical and statistical methods in this field can be resulted in some problems. Hence, the new research methods with abilities to infer meaning from complicated and ambiguous data seem useful. Therefore, along with identifying the traffic hot spots, adaptive Neuro-Fuzzy inference system is used to predict traffic hot spots on rural roads. In this process, a fuzzy inference system from Sugeno type is trained applying hybrid optimization routine (back propagation algorithm in combination with a least square type of method) and accident data of Karaj-Chalus road in Tehran Province. Then the system was tested by a complete set of data. Finally, the stated system could predict 96.85 % of accident frequencies in the studied blocks. Furthermore, the amount of effective false negative in all cases included only 0.82 % of predictions, which indicated a good approximation of predictions and model credibility. 相似文献
9.
Transportation is vital for the economic and social development and prosperity of every country. Weather phenomena can significantly affect transportation, having huge impacts on the economy and transport user safety. Research indicates that the road transportation system is the most vulnerable system to weather effects. Results from a nine-year period in Cyprus showed that extreme weather conditions resulted in a 5.8 % increase in fatalities on the roads. On the other hand, there is pressure to develop more environmentally sustainable materials to be used in roads, considering the availability of natural aggregate resources and the amount of waste concrete material arising from construction and demolition. This paper describes the use of recycled aggregate concrete (RAC) as a paving material in roads and its properties related to weather effects. Eight different concrete mixtures containing recycled concrete aggregates (RCA) were tested for the weather-related parameters of sorptivity, porosity and permeability. Results showed that the use of RCA and eventually RAC will affect the behaviour of road pavements, due to their higher sorptivity, porosity and permeability. However, it is believed that this will not be detrimental to the quality of road surfaces. 相似文献
10.
11.
Claudia Mignelli Daniele Peila Stefano Lo Russo Sara Maria Ratto Massimo Broccolato 《Natural Hazards》2014,73(1):23-35
Many kilometres of roads are close to rock slopes that are prone to rockfalls. The fulfilment of safety requirements in such situations is a multidimensional design process involving public and private technicians in the assessment and management of the problem. In this paper, a rockfall risk management approach has been applied to the road infrastructure network of the Regione Autonoma Valle D’Aosta, in order to calculate the level of risk and of its reduction using rockfall protection devices. In order to better understand the methodology, a comparative analysis of road accidents in Aosta Valley has been discussed. The road risk assessment was developed taking into account the absence of rockfall protection devices, and when they are present, different levels of efficacy have been considered. 相似文献
12.
Oil exploration and production (E&P) activities in remote regions are often considered a catalyst for landscape change through the direct alterations created by infrastructure features, as well as through the accessibility provided by roads. The construction, expansion and improvement of transportation routes in isolated areas can attract newcomers and resource users who engage in illegal logging, poaching, commercial agriculture, as well as planned and spontaneous colonization. These actions can lead to larger-scale surface disturbances that may also affect indigenous territories and natural preserves. However, do these parallel activities and outcomes always accompany E&P development, or can controlled access minimize changes? To answer this question we utilized an “accounting from above” approach that uses remote sensing and GIS techniques to analyze surface disturbance patterns linked to infrastructure features for both E&P and parallel activities. Our study area included four neighboring oil blocks in eastern Ecuador’s tropical forest, displaying three types of E&P development: public-access, controlled-access and roadless. The first objective was to determine the spatial relationship between infrastructure pattern, disturbance regimes and the type of road access for the year 2000 using land-use land-cover maps, soils data, protected areas and colonization zones. The second objective was to examine the statistical relationships between agricultural conversion and the above factors. Spatial analysis findings suggest that areas of overlap where colonization zones, public-access roads and fertile soils meet are most prone to deforestation. Statistical findings from a linear regression model suggest that the presence of public-access non-oil roads are significant at explaining the conversion of natural vegetation (forest) to agriculture, while the presence of protected areas helps explain the conservation of forested land. 相似文献
13.
Disruption of segments of roads can have a significant impact on the vulnerability of the entire network. Natural disasters are frequent causes of disruptions of this kind. This article focuses on determining the risk of road disruptions due to landslides. Our approach is based on methodology widely used in the field of epidemiology. We had available data on the location of the landslides, the road network and a list of the disrupted road segments. With the use of a 2 × 2 table, we determined the relationship between landslide data and road segment disruptions and derived the risk coefficient based on the number of landslides in the vicinity of the road and its length. The result is a disruption risk map with risk coefficients ranging from 0 to 47.94. In order to distinguish the most risky segments, we calculated a threshold of 12.40 with the use of a risk breakdown in a group of segments without damage. Nineteen percentage (402 km) of the road network in the Zlín region (Czech Republic), where the methodology was applied, is located beyond this threshold. The benefits of this approach stem from its speed and potential to define the most risky areas on which a detailed geomorphologic analysis can be focused. 相似文献
14.
K. Grewe 《GeoJournal》1979,3(1):27-34
In Brazil, new motor vehicles have to be conveyed by road truck even for distances as vast as 3,000 km or more, since the
railroad network is not efficient enough to handle them. However, the Brazilian government aims to extend the rail system
considerably as a means of uprating the country's infrastructure, relieving the load on urban areas and reducing diesel oil
consumption. VW do Brasil, as the largest industrial undertaking in the country, was requested by the Brazilian authorities
to submit a draft scheme for future utilization of the railroads following their expansion and modernization. A system of
13 destination railheads was thus conceived as an initial stage. In order to calculate alternative transportation costs a
special computer program was developed: with its aid movements of new vehicles from the factory to more than 800 dealers'
premises were optimized.
The implementation of this system would dispense with about two-thirds of the road trucks used to transport Volkswagen vehicles
within Brazil, and would thus relieve the roads of 71,600,000 truck kilometers per year.
In addition, the movement costs for new vehicles from VW do Brazil would drop by up to 20 %. However, it will not be possible
to implement this improvement within a short period, but only in stages concurrent with the long-term improvement of the Brazilian
railroads and, in particular, with the linking of the factory to the rail network.
In conjunction with similar studies conducted by other large industrial corporations in Brazil and details of the cost of
the projected railroad improvements and the system's running costs, it will be possible to produce a well-founded cost-benefit
analysis which may even be able to establish priorities for the individual routes. 相似文献
15.
Sheng Sheng Chi Xu Shaowei Zhang Shuqing An Maosong Liu Xuejiao Yang 《Environmental Earth Sciences》2012,65(7):1965-1975
Human activities have profoundly influenced natural ecosystems, especially wetlands. This study attempted to differentiate
the impact of human activities on reductions in wetland vegetation in the Lixiahe wetlands, China, at multiple spatial scales.
The reduction in wetland vegetation from 1988 to 2006 was quantified using Landsat data, and moving window analysis was used
to detect hot spots of vegetation reduction in the wetlands at window sizes of 150, 1,000 and 2,500 m. Logistic regression
was used to examine the influence on occurrence of the hot spots of landscape variables representing accessibility to human
settlements and roads. Over the study period, wetland vegetation declined by 69%, which was largely attributable to aquaculture
development. The hot spots of wetland vegetation reduction exhibited increasing patch size, but decreasing patch number with
increasing window size. The occurrence probability of the hot spots rose significantly with increasing proximity to rural
settlements and secondary roads, with only a minor response to the presence of towns. With increasing window size, however,
the density of secondary roads and rural settlements were less influential, whereas the presence of major roads had more influence
on hot spot occurrence. These trends are reasonable in that wetland use activities in the study area are directly associated
with the settlements and roads in the rural areas at local scales, but are also indirectly associated with the major transportation
network from a regional perspective. Overall, these results suggested that different human activities, as distinguished by
their sources on the landscape, could have different environmental consequences at different scales for scale-dependent features. 相似文献
16.
Zhaoling Zhang Shiliang Liu Shikui Dong Wei Fu Baoshan Cui 《Frontiers of Earth Science》2009,3(4):389-396
The construction of roads has direct and indirect impacts on soil erosion, with spatio-temporal variations existing among
different levels of road zones. Aiming to quantitatively analyze the soil loss, this paper explored the relationship between
the erosion of soil and its distance from the road in Fengqing county, Southwest China in 1987 and 2004, respectively. The
average soil erosion was calculated and expressed with grid map using universal soil loss equation (USLE) model based on GIS
and RS. Along the different levels of roads classified as trunk, county, town, village and unpaved road, the buffer zones
were subdivided into five stripes, each of which was 200 meters wide. The average soil erosion modulus of each buffer zone
was also counted. Results show that the soil loss decreases with increasing distance to the road except rare trunk roads in
the region. In addition, the declined intensity varies with the different levels of roads. Soil erosion was more serious along
the lower level road than the higher ones. And soil erosion was more severe for all levels of roads in 1987 than those in
2004 because much more rainfalls affected the situation of soil erosion in 1987. 相似文献
17.
Virginie Renson Nathalie Fagel Nadine Mattielli Serge Nekrassoff Maurice Streel Franois De Vleeschouwer 《Applied Geochemistry》2008,23(12):3253-3266
The ability of inorganic geochemistry to record environmental change and especially human impact has been evidenced by several studies across Europe, especially in peat, where it is possible to record the impact of agriculture, mining and other industries. However, despite the numerous investigations on the impact of ancient human activities such as ore mining and smelting, little attention has been paid to geochemistry as a tool to solve problems of palaeopollution in the surroundings of archaeological sites. This paper presents geochemical evidence of the impact of a possible early Roman road built in SE Belgian peatland. Increased Zn and Pb concentrations suggest that Pb–Zn ores were transported on the road. Lead isotope analyses suggest that these ores are locally derived, being compatible with those found in the nearby Pb–Zn ore deposits from East Belgium. Present results provide direct evidence that East Belgian Pb–Zn ores were already being mined during Roman times, i.e. earlier than previously suspected (i.e. 14th century) and that Zn appears to be relatively immobile here. On a broader scale, it also demonstrates that such an early road already had an impact on the environment in terms of metal pollution. This paper enlarges on the range of possibilities offered by geochemistry in the field of geoarchaeology. 相似文献
18.
Our research questions and analytical approaches are used to examine coupled human-natural systems in the Northern Ecuadorian Amazon. They are based on complexity theory and extend from our earlier work in Cellular Automata (CA) in which land use/land cover (LULC) change patterns were spatially simulated to examine deforestation and agricultural extensification on household farms. The basic intent is to understand linkages between people and the environment by explicitly considering pattern-process relationships and the nature of feedback mechanisms among social, biophysical, and geographical factors that influence LULC dynamics within the study area. In this research, we describe how our CA modeling approach emphasizes the human dimensions of LULC change by including socio-economic and demographic characteristics at the household-level along with biophysical data that describe the resource endowments of farms, geographic accessibility of farms to roads and communities, and the evolving nature of human-environment interactions over time and space in response to exogenous and endogenous factors.A LULC change scenario is examined by comparing model outcomes generated for a base CA model and an alternative CA model to explore the effects of increases in household income on land use change patterns at the farm level, achieved as a consequence of improved geographic accessibility to roads and communities and increased off-farm employment as a household livelihood strategy. Growth or transitions rules in our CA model, as well as neighborhood associations are sensitive to socio-economic and demographic factors of households, resource endowments of farms, geographic accessibility, and the uncertainty associated with peasant farming in a frontier setting. Model outcomes indicate that increases in household income are associated with more land in pasture and more land being cultivated for crops as a result of greater access to agricultural markets. In addition, more land in secondary forest succession occurs as a consequence of greater access to roads and communities, thereby, affording a better opportunity for off-farm employment and greater levels of household income. 相似文献
19.
三峡工程库区公路复建工程主要地质病害及防治对策 总被引：7，自引：4，他引：3
三峡工程建成后, 库水回水将淹没沿江(河) 地带的公路约1 000 km. 随着库区的开发, 不仅需要复建被淹没的公路, 恢复其功能, 而且还将大量修建新公路. 通过实例对三峡工程库区公路复建工程中的主要地质病害进行了论述, 指出已发生的地质病害主要是山区常见的滑坡、崩塌、泥石流, 而潜在的地质病害是由于水库库岸再造对公路工程的不利影响; 分析了产生病害的原因, 并提出了防治对策. 对三峡工程库区今后的公路建设、相似地质条件地区的道路建设均具有一定的参考和借鉴意义. 相似文献